The laboratory assessment of sperm DNA fragmentation in infertile patients

Over 15% of couples worldwide suffer from infertility and in 50% of cases a male factor is found. According to the World Health Organization, sperm analysis is the most appropriate test to assess male infertility. Since quite often, the conventional semen parameters are related to sperm DNA damage, the integration of this evaluation with sperm DNA fragmentation (SDF) could independently predict the sperm reproductive potential. Unfortunately, this analysis has not entered into routine clinical practice. The aim of this review is to discuss the importance of the SDF analysis and its clinical implication and to evaluate the extrinsic and intrinsic factors that affect the DNA fragmentation. In addition, principles and protocols of different methods used to evaluate and quantify the SDF are reviewed; advantages and disadvantages of different methods are reported.